Its factors are: 1, 2, 4, 5 and 10. As the sum of its factors is more than itself (i.e. 22), it can be referred to as an abundant number.

20 can been used as a number base. Remnants of this system remain in some European languages, for example in the English “score” (20) and the French “quatre vingts” (80, literally four groups of twenty). The old (pre-decimal) English monetary system enjoyed twenty shillings in a pound. The ancient Mayan numerical system – counting on fingers and toes – was a base 20 or "vigesimal" system.